FCC G4E - 业余无线电实践与电台操作

#G4E01🔗

What is the purpose of a capacitance hat on a mobile antenna?

移动天线上的电容帽有什么作用？

To increase the power handling capacity of a whip antenna

提高鞭状天线的功率处理能力

To reduce radiation resistance

降低辐射电阻

To electrically lengthen a physically short antenna

以电气方式延长物理上较短的天线

✓ 正确答案

To lower the radiation angle

降低辐射角

#G4E02🔗

What is the purpose of a corona ball on an HF mobile antenna?

高频移动天线上的电晕球的用途是什么？

To narrow the operating bandwidth of the antenna

缩小天线的工作带宽

To increase the “Q” of the antenna

增加天线的“Q”

To reduce the chance of damage if the antenna should strike an object

减少天线撞击物体时损坏的机会

To reduce RF voltage discharge from the tip of the antenna while transmitting

减少发射时天线尖端的射频电压放电

✓ 正确答案

#G4E03🔗

Which of the following direct, fused power connections would be the best for a 100-watt HF mobile installation?

以下哪种直接、带保险丝的电源连接最适合 100 瓦高频移动安装？

To the battery using heavy-gauge wire

使用粗规格电线连接至电池

✓ 正确答案

To the alternator or generator using heavy-gauge wire

使用粗规格电线连接至交流发电机或发电机

To the battery using insulated heavy duty balanced transmission line

到电池采用绝缘重载平衡传输线

To the alternator or generator using insulated heavy duty balanced transmission line

使用绝缘重型平衡传输线的交流发电机或发电机

#G4E04🔗

Why should DC power for a 100-watt HF transceiver not be supplied by a vehicle’s auxiliary power socket?

为什么 100 瓦高频收发器的直流电源不应该由车辆的辅助电源插座提供？

The socket is not wired with an RF-shielded power cable

插座未连接射频屏蔽电源线

The socket’s wiring may be inadequate for the current drawn by the transceiver

插座的接线可能不足以满足收发器消耗的电流

✓ 正确答案

The DC polarity of the socket is reversed from the polarity of modern HF transceivers

插座的直流极性与现代 HF 收发器的极性相反

Drawing more than 50 watts from this socket could cause the engine to overheat

从该插座汲取超过 50 瓦的功率可能会导致发动机过热

#G4E05🔗

Which of the following most limits an HF mobile installation?

以下哪项对高频移动安装的限制最大？

“Picket fencing”

“栅栏”

The wire gauge of the DC power line to the transceiver

连接至收发器的直流电源线的线规

Efficiency of the electrically short antenna

电短天线的效率

✓ 正确答案

FCC rules limiting mobile output power on the 75-meter band

FCC 规定限制 75 米频段移动设备输出功率

#G4E06🔗

What is one disadvantage of using a shortened mobile antenna as opposed to a full-size antenna?

与全尺寸天线相比，使用缩短的移动天线的缺点是什么？

Short antennas are more likely to cause distortion of transmitted signals

短天线更容易导致发射信号失真

Q of the antenna will be very low

天线的Q值会很低

Operating bandwidth may be very limited

操作带宽可能非常有限

✓ 正确答案

Harmonic radiation may increase

谐波辐射可能会增加

#G4E07🔗

Which of the following may cause receive interference to an HF transceiver installed in a vehicle?

以下哪项可能会对安装在车辆中的高频收发器造成接收干扰？

The battery charging system

电池充电系统

The fuel delivery system

燃油输送系统

The control computers

控制计算机

All these choices are correct

所有这些选项都是正确的

✓ 正确答案

#G4E08🔗

In what configuration are the individual cells in a solar panel connected together?

太阳能电池板中的各个电池以什么配置连接在一起？

Series - parallel

串联-并联

✓ 正确答案

Shunt

分流器

Bypass

旁路

Full-wave bridge

全波电桥

#G4E09🔗

What is the approximate open-circuit voltage from a fully illuminated silicon photovoltaic cell?

完全照明的硅光伏电池的开路电压大约是多少？

0.02 VDC

0.02伏直流

0. 5 VDC

0.5伏直流

✓ 正确答案

0.2 VDC

0.2伏直流

1.38 VDC

1.38伏直流

#G4E10🔗

Why should a series diode be connected between a solar panel and a storage battery that is being charged by the panel?

为什么要在太阳能电池板和由电池板充电的蓄电池之间连接串联二极管？

To prevent overload by regulating the charging voltage

通过调节充电电压来防止过载

To prevent discharge of the battery through the panel during times of low or no illumination

防止在光照不足或无光照时电池通过面板放电

✓ 正确答案

To limit the current flowing from the panel to a safe value

限制从面板流出的电流至安全值

To prevent damage to the battery due to excessive voltage at high illumination levels

防止高照度下电压过高而损坏电池

#G4E11🔗

What precaution should be taken when connecting a solar panel to a lithium iron phosphate battery?

连接太阳能电池板和磷酸铁锂电池时应采取哪些预防措施？

Ground the solar panel outer metal framework

将太阳能电池板外部金属框架接地

Ensure the battery is placed terminals-up

确保电池端子朝上放置

A series resistor must be in place

必须安装串联电阻

The solar panel must have a charge controller

太阳能电池板必须有充电控制器

✓ 正确答案

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FCC G4E - 业余无线电实践与电台操作

小节 G4E：业余无线电实践与电台操作